1. Field of the Invention
The present invention relates to a touch pad which is mounted on a personal computer and the like.
2. Description of the Related Art
In recent years, touch pads have become widespread which have a so-called multi-touch gesture recognition function of recognizing the movement of a plurality of fingers that are touched on a touch pad.
Incidentally, in a case of a single touch in which a touch of one finger is performed, there is a great tendency for an operation to be performed using a finger such as an index finger or a middle finger which is capable of being reliably touched to an operation surface. On the other hand, in a case of a large number of fingers like in a multi-touch, it may depend on a structure of a hand, and there is a tendency for a touch operation to be performed through a lateral side of a thumb or a fingertip. For this reason, in a case of a large number of fingers, there is a tendency for a touch area, a touch duration, and the like to be reduced as compared with a case of a small number of fingers. Accordingly, in a case of a large number of fingers, even when a finger is touched to an operation surface, the finger may be determined to be a finger floating in the air, and thus there is a problem in that the finger is not determined to be an operation valid target finger. In order to solve this problem, a determination condition such as a touch area and a touch duration may be loosely set. However, in that case, the finger floating in the air may be often determined to be an operation valid target finger, which results in another problem.
US Unexamined Patent Application Publication No. 2008/0087477 discloses that when a signal intensity exceeds a predetermined threshold value, it is determined that there is a touch of a finger, but there is the above-described problem.